Processes and systems for using silica particles in fluid bed reactor

Abstract

The present disclosure relates to fluid bed processes that utilize silica particles as a fluidization aid. The process comprises reacting one or more reactants in a reactor comprising a fluid bed to form a product. The fluid bed comprises a catalyst composition comprising a catalyst and an inert additive composition comprising silica particles from 0.5 wt % to 30 wt %, based on the total weight of the catalyst composition. The silica particles are discrete, inert particles that are mixed with the catalyst in the fluid bed.

We claim: 
     
       1. A process comprising:
 reacting one or more reactants in a reactor comprising a fluid bed to form a product; 
 wherein the fluid bed comprises a catalyst composition comprising a catalyst and an inert fluidization aid comprising from 0.5 wt % to 30 wt % of silica particles, based on the total weight of the catalyst composition, 
 wherein the silica particles have an equivalent median particle diameter ranging from 10 microns to 500 microns and a sphericity ranging from 60% to 99.9%. 
 
     
     
       2. The process of  claim 1 , wherein the catalyst comprises one or more of antimony, uranium, iron, bismuth, vanadium, molybdenum, nickel, potassium, cobalt, oxides thereof, or salts thereof. 
     
     
       3. The process of  claim 1 , wherein the catalyst has an equivalent median diameter ranging from 1 microns to 125 microns. 
     
     
       4. The process of  claim 1 , wherein the silica particles have a real density ranging from 1.8 g/cm 3  to 2.8 g/cm 3 , and wherein the difference between the density of the silica particles and the catalyst is less than 75%. 
     
     
       5. The process of  claim 1 , wherein the silica particles have a surface area less than 50 m 2 /g, and wherein the silica particles have a hardness ranging from 500 to 720 as measured by ASTM E384 (2018). 
     
     
       6. The process of  claim 1 , wherein the catalyst composition further comprises alumina particles, wherein a weight ratio of alumina particles to silica particles is less than 1:1. 
     
     
       7. The process of  claim 1 , wherein the fluidization aid comprises no alumina. 
     
     
       8. The process of  claim 1 , wherein the process reduces consumption of the catalyst by greater than 5% per kilogram of product produced, as compared to an otherwise identical process using fluidization aids other than the silica particles. 
     
     
       9. The process of  claim 1 , wherein the silica particles reduce erosion of the reactor by greater than 10% compared to an otherwise identical a similar process conducted without from 0.5 wt % to 30 wt % of the silica particles. 
     
     
       10. The process of  claim 1 , wherein the process demonstrates a product yield greater than 0.2% greater than that of an otherwise identical a similar process conducted without from 0.5 wt % to 30 wt % of the silica particles. 
     
     
       11. The process of  claim 1 , wherein the silica particles have a real density ranging from 2.1 g/cm 3  to 2.5 g/cm 3 , wherein the silica particles have a surface area less than 1 m 2 /g, wherein the silica particles have a hardness ranging from 500 to 720 as measured by ASTM E384 (2018), and wherein the product yield is greater than 70%. 
     
     
       12. The process of  claim 1 , wherein the silica particles have an equivalent median particle diameter ranging from 20 microns to 100 microns, wherein the silica particles have a real density ranging from 2.1 g/cm 3  to 2.5 g/cm 3 , wherein the silica particles have a sphericity greater than 67%, wherein the silica particles comprise greater than 99 wt % silica, wherein the product yield is greater than 70%. 
     
     
       13. A process for producing an acrylonitrile product, the process comprising:
 reacting one or more reactants in an ammoxidation reactor comprising a fluid bed under ammoxidation conditions to form the acrylonitrile product; 
 wherein the fluid bed comprises a catalyst composition comprising a catalyst and an inert fluidization aid silica particles having a density from 1.8 g/cm 3  to 2.8 g/cm 3 , 
 wherein the silica particles have a sphericity ranging from 60% to 99.9%. 
 
     
     
       14. The process of  claim 13 , wherein the difference between the density of the silica particles and the catalyst is less than 75%, wherein the process demonstrates an acrylonitrile product yield greater than 0.2% greater than that of an otherwise identical process conducted without the silica particles. 
     
     
       15. The process of  claim 13 , wherein the one or more reactants comprises an olefin, ammonia, and an oxygen-containing gas.